On Mon, Apr 25, 2011 at 08:21:21PM -0400, Michael Stevens wrote:
>Is there a preferred method for getting variables using randomint() to stop
>getting defined once they're set, eg, avoid this;
>
> !! Redefinition of a constant scalar "rnd" (was 2786 now 195)
> !! Redefinition of a constant scalar "rnd" (was 195 now 2749)
> !! Redefinition of a constant scalar "rnd" (was 2749 now 1852)
>
>
>I'm trying to set a randomized 0/60 minute delay on a command that runs once
>a day so that all the machines don't fire right at the same time and overload
>a file server the command tells them to grab a bunch of files from. If there's
>a better way to do this than embedding an "at" or "sleep" in my command, let
>me know ...
This isn't a direct answer to your question, but I had to do something
similar. I wanted the clients to consistantly choose a host from a
list (it happens to be a list of two hosts, but the idea should scale).
I used something like this (untested, use at own risk, formatting
adjusted for clarity in email):
bundle agent foo {
vars:
hostname_hash string => hash(getenv("HOSTNAME","40"),'md5');
servername string => execresult(
"/bin/echo
${hostname_hash} |
/bin/cut -c -16 |
perl -e perl
statement could'll=qw(hostA hostB);'
-e
'$L=scalar @l;'
-e 'print $l[hex(<>)%$L];'
"useshell");
}
I actually think this a bit better than a purely random number that
changes each time. This should give you a "random", but consistant
value for each hostname.
In your case, you just want a number 0-60, so the execresult command
could be replaced with something like:
/bin/echo ${hostname_hash} |
/bin/cut -c -16 |
perl -e 'print <>%61;'"
Note that I've clipped only 16 characters, instead of the full 32 that
come from md5sum, in order to avoid integer overflows in Perl.
--
Jesse Becker
NHGRI Linux support (Digicon Contractor)
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